Comment 7 for bug 1671891

Thanks for the triage, Larry.

This bug seems to occur only when an automatic IP address is set as the gateway link. The issue is that during deployment, MAAS allocates a new IP address and replaces the old one. This invalidates the gateway link, but the gateway link isn't properly cleared out by Django. (If it was, we never would have noticed this, AND the node wouldn't get the correct gateway!)

The simplest fix is to avoid replacing the address; instead delete the newly-allocated address and "steal" its IP address for the existing entry.